Abiotic factor light

Abiotic environmental factors and their relevance for plants

We use the term “abiotic environmental factors” to denote factors deriving from the non-living environment that have direct or indirect impact on living organisms like humans, animals and plants. The term is clearly distinguished from “biotic” factors, which denotes impacting factors from the living environment.

Typical examples of abiotic environmental factors are light, water, temperature, oxygen content, air humidity or wind velocity. All these factors impact the world of plants in general and define certain aspects like growth, flower formation or germination of the seeds. To reach a desired result when it comes to growing and/or breeding plants, both the abiotic and biotic factors need to meet certain conditions. The specific requirements depend on the type of plant. While shadeloving plants are dependent on high levels of air humidity, light plants usually prefer dry air.

The abiotic factor of light is not only important for plant growth but indispensable for flowering and germination. Plants use light as an energy source to convert inorganic substances like CO2 and water into organic material like glucose, amino acids and lipids. Light has a unique spectral composition. It is indispensable for photosynthesis and provides the basis for plant life. Of course it applies as well that each type of plant has individual needs concerning the intensity of light. While shade-loving plants reach their maximum photosynthetic capacity with low light intensity, light plants are dependent on high light intensity.

To understand the needs of plants when it comes to light a basic understanding of the sun’s radiation spectrum is necessary.

The spectral composition of light and its effects on plants

Natural sunlight is essentially electromagnetic radiation which is emitted with a certain intensity and wavelength. The electromagnetic spectrum of light covers more than the visible spectrum and exhibits its peak of intensity at about 500 nm. The shorter the wavelength, the higher the energy level of the lightwaves. Concerning plant growth and flowering it is important to understand that plants need the whole spectrum of natural light for optimal growth.

With synthetic lighting setups it is a common practice to focus on the wavelengths around 660 nm and 450 nm. This wavelength range is generally understood to deliver the energy needed by plants for growth, flowering and photosynthesis in general.

However, in his scientifically approved study from 1972 Dr. McCree discovered that the energy levels provided by the red and blue wavelengths alone are not sufficient for maximum physiological development of plants. Examining 22 different types of plants Dr. McCree showed that carbon-fixation, a crucial element of photosynthesis, is taking place using almost the whole range of the visible light spectrum.

As a result it is essential to provide a light spectrum which is as authentic as possible to ensure balanced, healthy and sustainable plant growth. While conventional grow lights usually only provide red and blue wavelengths, lighting systems based on the McCree curve cover the yellow and green frequencies as well. These lighting systems manage to closely approximate the wavelength spectrum of the sun and offer lighting conditions that resemble the plant’s natural environment.

Next to reproducing the natural light spectrum as close as possible, critical factors for successful artificial lighting include light intensity and periods of exposure to light. Both, light intensity and periods of exposure are dependent on the individual needs of the type of plant you are growing and both factors have major impact on plant growth and flowering. Studies on photoperiodism have shown that short-day plants prefer shorter periods of exposure to light than long-day plants.

Using state of the art semi-conductors, grow lights with LED technology meet the requirements described above exceedingly well. Lights like our Sunflow offer excellent reproduction of the scientifically approved McCree spectrum, highly efficient modes of operation and long durability.

The abiotic factor light is the most important factor when it comes to plant growth. Scientific studies show that successful artificial lighting depends on offering lighting conditions that are as close to natural light as possible.